Catalyst and method of polyester polymerization

ABSTRACT

A catalyst, containing a ketone peroxide, e.g., methyl ethyl ketone peroxide, and an organic non-ketonic diperoxide, e.g., 2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxy)hexane, is used to cure polyester resins containing over 900 p.p.m. of an inhibitor. A small amount of sodium methoxide can be used as part of the catalyst. More specifically, polyester resins containing 900 to 40,000 p.p.m. of inhibitors can be cured within 10 minutes to 24 hours with the novel catalyst.

25299. AU 165 EX U United States Patent 1151 3,668,139

Daniels et al. 1 1 June 6, 1972 [5 CATALYST AND METHOD OF 3,086,9664/1963 Mageli =1 a1 ..260/610 11. POLYESTER POLYMERIZATIQN 3,231,5421/1966 Eisinger et a1. ....2s2/426 3,318,974 5/1967 Montesano ..252/426[72] inventors: David A. Daniels, Kendall Park, N.J.;

Rowland L. Orem, Jr., Baltimore; Edwin FOREIGN PATENTS OR APPLICATIONS827,511 2/1960 Great Britain ..252/186 [73] Assignee: W. R. Grace 8:Co., New York, NY.

.y Examiner-Herbert B. Guynn Assistant Examiner-Irwin Gluck PP 1 1Attorney-Kenneth E. Prince Related US. Appllcltion Data [57] ABSTRACT[62] g z g 1968 A catalyst, containing a ketone peroxide, e.g., methylethyl ketone peroxide, and an organic non-ketonic diperoxide, e.g., [52]Us C 252/186 252/99 252/426 2,5-dimethyl-2,5-bis(Z-ethyl hexanoylperoxy)hexane, is used 260/610 R 266/016 to cure polyester resinscontaining over 900 p.p.m. of an in 511 111:. c1. ..'..coa 51 7 c0773/00 A sdium 5s Field 61 Search ..252/l86, 99, 426-, 260/610 R, P Ofcatalyst Mm spccifically' "Sins 2 0 7 T, mg 23 40 R taining 900 to40,000 p.p.m. of inhibitors can be cured within 10 minutes to 24 hourswith the novel catalyst.

[56] References Cited 2 U I No Damn,

UNITED STATES PATENTS 2,996,549 8/1961 Mageliet al. ..252/426 CATALYSTAND METHOD OF POLYESTER POLYMERIZATION CROSS-REFERENCE TO RELATEDAPPLICATION This is a divisional of copending application Ser. No.782,734, filed Dec. 10, 1968, and now US. Pat. No. 3,575,918.

The invention herein described was made under a contract or subcontractthereunder, with the Department of the Air Force, Department of Defense.

BACKGROUND OF THE INVENTION 1 Objectives of the Invention An object ofthis invention is to provide a process to cure polyester resins whichcontain very large amounts of inhibitors. A further object is to providea novel catalyst for such a process. Other objects and advantages ofthis invention will be apparent to one skilled in the art from thefollowing specification and claims.

2. Prior Art It is generally known that the polymerization of polyesterresin systems containing more than 100 parts per million (p.p.m.) of aninhibitor is extremely diflicult and that the resultant cured resinsgenerally have reduced physical properties. An inhibitor is a materialwhose primary function is to retard internal polymerization of thepolyester constituent of the resinous composition.

A polymerization catalyst is disclosed in U.S. Pat. No. 3,214,496 whichcomprises hydrogen peroxide, an organic peroxy compound and amonocarboxylic acid. US. Pat. No. 3,377,407 discloses a polymerizationcatalyst which comprises 3 ,3-dimethyl-3 ,S-dihydroxy-l,2-peroxycyclopentane and methyl ethyl ketone peroxides. That patentstates that rapid cures can be obtained when large amounts of inhibitorsare present by increasing the quantity of the methyl ethyl ketoneperoxide. The only examples utilized less than 100 p.p.m. of inhibitor.Also, it states that the effectiveness of the ketone peroxide isenhanced by the presence of a metal activator or an amine along with themetal activator. US. Pat. No. 3,188,363 discloses aninhibitor-stabilizer system (mixture of copper and hydrazine additionsalts) which are promoters in the presence of polymerization catalysts,such as methyl ethyl ketone peroxide. The patent states that up to10,000 p.p.m. of hydrazine addition salt and 800 p.p.m. of copper (basedon the polyester resin) can be used. Example 46 discloses the use ofmethyl ethyl ketone peroxide to cure a polyester resin, containing 800p.p.m. hydrazine hydrochloride, in about twothirds hour. The use of2,5-dimethyl-2,5-di(t-butylperoxy)hexane to crosslink polyethylene isdisclosed in US. Pat. No. 3,086,966.

The use of mixtures of peroxides as unsaturated polyester polymerizationcatalysts is disclosed in Polyester Polymerization with Mixed CatalystSystems, Lucidol Technical Publications, Wallace & Tiernan, Inc.,Lucidol Division, Buffalo, N .Y. [undated, but stated to be based on apaper presented by Harrison et al. at the 1960 S.P.I. ReinforcedPlastics Division meeting in Chicago, Illinois]. That publicationdiscloses the use of methyl ethyl ketone peroxide and dit-butyldiperoxyphthalate to polymerize an unsaturated polyester resincontaining 0.013 weight percent inhibitor (130 p.p.n1.). Thatpublication further disclosed that "the high-temperature componentshowed no appreciable activity" when tested at 212 F. In fact,2,5-dimethylhexane-2,S-dihydroperoxide is stated to be an inhibitor whenused in combination with methyl ethyl ketone peroxide to cure thelow-inhibitor-content polyester resin.

BROAD DESCRIPTION OF THE INVENTION The process of this inventionincludes curing polyester resin systems, preferably unsaturatedpolyesters, which contain over 900 ppm. of inhibitor. The process isextremely effective in curing polyester resin systems containing about900 to about 40,000 ppm. of inhibitor. The cure takes from about 10minutes to about 24 hours. The resultant cured polyester resin has verygood properties. The polyester resin systems to be cured can containpromoters, fillers, etc. The curing is achieved by the use of a novelcatalyst. Depending upon the amount of inhibitor present, from about 2to about l0 weight percent of the novel catalyst can be utilized. Thenovel catalyst includes at least one ketone peroxide or hydroperoxideand at least one organic non-ketonic diperoxide or dihydroperoxide, theweight ratio of the two respective components ranging from about 2: l toabout 4: l. The ketone component can also be a polyperoxide orpolyhydroperoxide, where poly is defined as two or more, i.e., di-,tri-, etc. As used within the scope of this invention, the term peroxidecan include the tenn hydroperoxide and can include the monoandpoly-peroxides. The catalyst can contain up to about 2 weight percentsodium methoxide if the inhibitor is of the phenolic type.

DETAILED DESCRIPTION OF THE INVENTION The useful ketone rnonoperoxidecompounds of this invention contain the groupings:

Several useful monoketone peroxides are the various methyl ethyl ketoneperoxides, methyl isobutyl ketone peroxides, dimethyl ketone peroxides,diethyl ketone peroxides, di n-undecyl ketone peroxides, methyl vinylketone peroxides, methyl phenyl ketone peroxides, diphenyl ketoneperoxides, di-n-propyl ketone peroxides, diisopropyl ketone peroxides,di-n-butyl ketone peroxides, di-sec-butyl ketone peroxides, ditert-butylketone peroxides, di-n-amyl ketone peroxides, di-nhexyl ketoneperoxides, di-n-heptyl ketone peroxides, di-noctyl ketone peroxides,di-n-decyl ketone peroxides, di-ntridecyl ketone peroxides,di-n-heptadecyl ketone peroxides, methyl n-propyl ketone peroxides,methyl isopropyl ketone peroxides, methyl n-butyl ketone peroxides,methyl isobutyl ketone peroxides, methyl sec-butyl ketone peroxides,methyl tert-butyl ketone peroxides, methyl n-amyl butyl ketoneperoxides, methyl isoamyl ketone peroxides, methyl n-hexyl ketoneperoxides, methyl isohexyl ketone peroxides, methyl nheptyl ketoneperoxides, methyl n-octyl ketone peroxides, methyl n-nonyl ketoneperoxides, methyl n-decyl ketone peroxides, methyl n-heptadecyl ketoneperoxides, ethyl npropyl ketone peroxides, ethyl n-butyl ketoneperoxides, propyl isopropyl ketone peroxides, methyl cyclopropyl ketoneperoxides, methyl ethynyl ketone peroxides, methyl isopropenyl ketoneperoxides, methyl propenyl ketone peroxides, 4- methyl-3-penten-2-oneperoxides, S-hexen-Z-one peroxides, 3-hepten-2-one peroxides,3,5-heptadien-2-one peroxides, 2,6-dimethyl-2,5-heptadien-5-oneperoxides, 5-hydroxy-4-octanone peroxides, l-chloro-Z-propanoneperoxides, l-bromo- 2-propanone peroxides, l,l-dichloro-Z-propanoneperoxides, l,3-dichloro-2 -propanone peroxides, cyclobutanone peroxides,cyclopentanone peroxides. pimelic peroxides, Z-methylcyclohexanoneperoxides, cycloheptanone peroxides, cyclopentadecanone peroxides,Z-camphanone peroxides, fenchone peroxides, a-ionone peroxides,3,5,5-trimethyl-2- hexen-l-one peroxides, B-ionone peroxides, carvoneperoxides, phenyl tert-butyl ketone peroxides, phenyl butyl ketoneperoxides, phenyl propenyl ketone peroxides, phenyl undecyl ketoneperoxides, phenyl vinyl ketone peroxides, 4-phenyl-3- buten-Z-oneperoxides, methyl Z-naphthyl ketone peroxides, methyl l-naphthyl ketoneperoxides, chalcone peroxides, mchloroacetophenone peroxides, benzylphenyl ketone peroxides, l-naphthyl phenyl ketone peroxides,a-hydroxy-a-phenylacetophenone peroxides, biphenylene ketone peroxides,N,N-tetramethyl-4,4-diarninebenzophenone peroxides, xanthone peroxides,flavone peroxides, and S-hydroxy-Z- (hydroxymethyl)-4-pyrone peroxides.

The monoketones, which can be converted into useful analagous monoketoneperoxides, can be prepared by the methods given in and references citedin Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd Edition,lnterscience Publishers, N.Y., Vol. 12(1967), pp. 124-138.

Several useful 1,2-diketone peroxides are 1,2-cyclopentanedioneperoxides, 3-methyl-l,2-cyclopentanedione peroxides,1,2-cyclohexanedione peroxides, 2,3-butanedione peroxides,2,3-pentanedione peroxides, 3,4-hexanedione peroxides,4-methyl-2,3-pentanedione peroxides, 3,4-heptanedione peroxides,5-methyl-2,3-hexanedione peroxides, 4,5-octanedione peroxides,2,S-dimethyl-3,4-hexanedione peroxides,2,2,5,5-tetramethyl-3,4-hexanedione peroxides, diphenylglyoxalperoxides, di-2-furfuroyl peroxides, methylphenylglyoxal peroxides,phenyl benzylglyoxal peroxides, and 4,4- dimethyxybenzil.

The l,2-diketones, which can be converted into useful analagous1,2-diketone peroxides, can be prepared by the methods given in andreferences cited in Kirk-Othmer, Encyclopedia of Chemical Technology,2nd Edition, lnterscience Publishers, N.Y., Vol. 12(1967), pp. 142-144.

Several useful 1,3-diketone peroxides are 2,4-pentanedione peroxides,2,4-hexanedione peroxides, 2,4-heptanedione peroxides,5-methyl-2,4-hexanedione peroxides, 5,5- dimethyl-2,4-hexanedioneperoxides, tanedione peroxides, 2,2-dimethyl-3,S-nonanedione, 3,3-diethyl-2,4-pentanedione, l-cyclohexyl-1,3-butanedione peroxides,5,5-dimethyl-l,3-cyclohexanedione peroxides, lphenyl-l,3-butanedioneperoxides, l-(4-biphenylyl)-l,3-butanedione peroxides,l-phenyl-l,S-pentanedione peroxides,lphenyl-S,S-dimethyl-Z,4-hexanedione peroxides, l-pheny1-3-(2-methoxy-phenyl)-l ,3-propanedione peroxides, l-(4-nitrophenyl)-1,3-butanedione peroxides, l( 2-furyl)- l ,3-butanedioneperoxides, and l-(tetrahydro-2-furyl)-l,3-butanedione.

The 1,3-diketones, which can be converted into useful analagousl,3-diltetone peroxides, can be prepared by the methods given in andreferences cited in Kirk-Othmer, Encyclopedia of Chemical Technology,2nd Edition, lnterscience Publishers, N.Y., Vol. 12 (l967),pp. 154-156.

Several useful 1,4-diketone peroxides are 2,5-hexanedione peroxides,2,5-octanedione peroxides, 6-methyl-2,5-heptanedione peroxides,2,5-decanedione peroxides, 2,5-undecanedione peroxides,2,5-dodecanedione peroxides, 3,6- dodecanedione peroxides,2,5-octadecanedione peroxides, and l l-methoxy-2,5-undecanedioneperoxides.

The 1,4-diketones, which can be converted into useful analagousl,4-diketone peroxides, can be prepared by the methods given in andreferences cited in Kirk-Othmer, Encyclopedia of Chemical Technology,2nd Edition, lnterscience Publishers, N.Y., Vol. 12 (1967), PP- 159-161.

The useful ketone peroxide compounds are usually prepared by theaddition of hydrogen peroxide, alkyl hydroperoxides, or peroxycarboxylicacids to the carbonyl group of the ketones. Ketones and hydrogenperoxide, in solution, give mixtures of addition and condensationproducts of structures (i) to (viii), which follow:

cyclic gem-diperoxides (vi) gum-dihydroperoxides (ll)3-ethyl-2,4-penpoly mm'ic a-oxy-mul a-purwherein R can be the same ordifferent alkyl, aralkyl or aryl radical, or hydrogen. The reactionconditions and the ketone structure determine which peroxy structurepredominates and with the lower molecular weight ketones, most of thesestructures apparently exist in equilibrium. Polymeric peroxides of thegeneral structure, H(OOCR,R ),,--OOH, wherein R and R, are the same ordifferent alkyl groups and/or branched alkyl groups, are also formedwith many ketones, e.g., acetone, ethyl methyl ketone, and diethylketone.

U.S. Pat. No. 3,149,126 describes, among others, the following usefulketone peroxides:

(a) CH2 OII In many cases, to achieve a high degree of purity of onetype of useful ketone peroxide, a relatively high boiling stabilizermust be added. An example of such a stabilizer is dimethyl phthalate.

Ethyl isoamyl ketone peroxide (an essentially pure product) can be madeby the process given in U.S. Pat. No. 3,15 l,l70.

In general, solvents which are suitable for the useful ketone peroxidesare those organic solvents which have a relatively high volatility, thatis, those having a boiling temperature below that of the ketoneperoxide. In general, the preferred organic liquid solvents fall in theclass of alkanols, glycols including ether glycols, ethers, ketones,esters, heterocyclic amides, and heterocyclic alcohols. Mixtures ofthese solvents may be used. Also, water containing solutions of thesesolvents may be used. Particularly desirable species of solvents formethyl ethyl ketone peroxides are propylene glycols andtetrahydrofurfuryl alcohol. Although the active oxygen content of theformulation can vary widely; in general, the formulations are made up tohave an active oxygen content of between about 1 and 6 percent, e.g., 4percent.

Suitable solvents for ethyl isoamyl ketone peroxide are diethyl etherand ethyl isoamyl ketone.

Examples of non-ketonic organic diperoxides and dihydroperoxides are (a)2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxy) hexane, (b)2,5-dimethyl-2,5-di(t-butylperoxy)hexane, (c)2,5-dimethylhexane-2,5-di(peroxylaurate), (d)

2,5-dimethyl-2,5-di(methylperoxy)hexane, (e)2,5-dimethylhexane-2,5-di(peroxy-ethylcarbonate (f) l, l ,4,4-tetramethyl-7-benzyl-cyclo-4,7-diperoxynonane, (g) 2,5-dimethylhexane-2,5-dihydroperoxide, (h) di-t-butyl diperoxyphthalate,and (i) 2,5-dimethylhexane-2,S-diperoxybenzoate.

2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxy)hexane can be obtained in asolvent as Lupersol 256 which is a trade designation and which iscommercially available from Wallace & Tieman, lnc. 2,5-dimethyl-2,5-di(t-butylperoxy)hexane can be prepared by the method given in US. Pat. No.3,086,966. Organic diperoxides (c) through (f) can be prepared by themethod given in U.S. Pat. No. 3,1 17,166.

The catalyst system of this invention can obtain between 0.2 and 2.0weight percent of sodium methoxide when an inhibitor of the picric acidtype is present in the polyester resin system.

As defined within the scope of this invention, an inhibitor is amaterial whose primary function is to retard or inhibit inter nalpolymerization of the polyester constituent of the resinous composition.An inhibitor can therefor alternatively be termed a stabilizer." Avariety of phenolic materials have been used heretofore as inhibitorsfor this purpose. Among such materials are phenol itself, the monoalkylphenols, such as for example, ortho-, meta-, para-cresol, a mixture ofsaid isomers; alkyl phenols having a plurality of such substituents asethyl, propyl, butyl and higher alkyl radicals attached to the ring; andthe like. Also, the polyhydric phenols may be used, such as catechol,resorcinol, hydroquinone or mixtures of these or partially alkylatedpolyhydric phenols, including such compounds as tertiary-butyl catecholand compounds which 7 have several alkyl groups present. Also operableare the phenols which have alkoxy groups present such as eugenol,guaiacol and similar phenols. Other specific phenolic materials arep-benzoquinone, 2,5-di-phenyl-p-benzoquinone, 2,5-dt-amyl hydroquinone,2,5-di-t-butyl hydroquinone, toluhydroquinone, 2,5-di-t-butyl quinone,p-octylphenyl salicylate, resorcinol mono benzoate, 2,4,5-trihydroxybutyrophenone, 2,5-diphenol quinone, monotertiary butyl and toluquinone.

Other inhibitors are tetrabromocatechol, picric acid, 2,4-dinitrophenol, N-nitrosodiethylamine, dinitro-o-cresol, etc. The amountof inhibitor which can be overcome by the catalyst of this inventiongenerally ranges from about 900 to about 40,000 ppm. by weight based onthe mixture of polyester resin, catalyst and promoter. This depends inpart on the nature of the polyester resin, etc.

Any of the various known polyester resin systems containing up to 40,000p.p.m. of inhibitor can be cured by the catalyst system of thisinvention. Various useful polyester resin systems are given in thefollowing paragraphs.

The prefered unsaturated polymerizable mixtures to be cured by theprocess of this invention are conventional classes of resins known inthe prior art. The most preferred polyester resins are prepared by theesterfication of alpha, beta unsaturated polybasic acids, and dihydricalcohols. Certain compounds of this type may be indicated generically asfollows:

MG-MGMG where, M-- represents an unsaturated dibasic acid residue andGrepresents a dihydric alcohol residue. Modifying dibasic acids may alsobe used in the polyester resin compositions. Representative dihydricalcohols and unsaturated polybasic acids are shown below.

In preparing unsaturated polyesters which may be employed in thepractice of the present invention, the alcohol component may compriseethylene glycol, diethylene glycol or propylene glycol, or one of thegroup of solid polyethylene glycols designated as Carbowax."

Polyethylene glycols such as the Carbowaxes" are understood to havemolecular weights above 300. Those most useful for this invention haveweights below 4,000 and preferably are in a range of about 1,000 to2,000, e.g., 1,500.

The acid component usually comprises an alpha, betaethylenicallyunsaturated polycarboxylic acid such as maleic, fumaric or itaconicacid, or the well-known derivatives of these polycarboxylic acids havingethylenic unsaturation in alpha-beta relation to the carboxyl group.Polybasic acids such as aconitic acid, tricarballylic acid or citricacid may also be employed. A plurality of such acids also may be mixedwith each other, if so desired. in many instances, it may be desirableto include a dicarboxylic acid free of ethylenic unsaturation. Examplesof this latter type of dicarboxylic acid include phthaiic acid orterephthalic acid, which, although they contain double bonds in thebenzene ring, do not undergo addition reaction with monomer compoundsand may, therefore, be considered as being the equivalent of saturatedcompounds. Likewise, aliphatic dicarboxylic acids such as succinic acid,adipic acid, sebacic acid, or azelaic acid may be substituted for a partof the alpha, beta-ethylenically unsaturated dicarboxylic acid. Theproportion of the non-ethylene acid with respect to the alpha,beta-ethylenecally unsatureated acid is susceptible of wide variation. Amolecular proportion of 0.25 to 12 moles of saturated acid and/oraromatic diacids per mole of unsaturated acid is usually used forcommercial applications.

in preparing the polyester, a small excess (usually 5 or 10 percent) ofthe dihydric alcohol is usually employed. The conditions of theesterification reaction are those conventionally employed in preparingesters. For example, the mixture of the alcohol and the acid is heatedin a vented container or under an inert atmosphere until thestoichiometric amount of water of reaction is expelled from the system,which usually occurs in a temperature range of about to 200 C. Thereaction is continued until water ceases to evolve or until the acidvalue is reduced to a reasonable low point, e.g., within a range ofabout 5 to 50, or until the mixture becomes highly viscous or even solidwhen it is cooled. Usually these conditions are attained in a period of2 to 20 hours. In any event, the reaction is concluded before theproduct becomes infusible and insoluble because of the advanced stage ofpolymerization.

The ethylenically unsaturated monomers may be selected from thefollowing general list:

1. Monoolefinic hydrocarbons, that is, monomers containing only atoms ofhydrogen and carbon, such as styrene, alpha-methyl styrene, alpha-ethylstyrene, alpha-butyl styrene and vinyl toluene, and the like;

2. Halogenated monoolefinic hydrocarbons, that is, monomers containingcarbon hydrogen and one or more halogen atoms such asalpha-chlorostyrene, alphabromostyrene, 2,5-dichlorostyrene,2,5-dibromostyrene, 3,4- dichlorostyrene, 3,4-difluorostyrene, ortho-,metaand parafluorostyrenes, 2,6-dichlorostyrene, 2,6-difluorostyrene, 3-fluoro-4-chlorostyrene, 2,4,5-trichlorostyrene,dichioromonofluorostyrenes, chloroethylene (vinyl chloride),l,l-dichloroethylene (vinylidene chloride), brornoethylene,fluoroethylene, iodo-ethylene, l,l-dibromoethylene, l,ldifluoroethylene,l, l-diiodoethylene, and the like.

3. Esters of organic and inorganic acids such as vinyl acetate, vinylpropionate, vinyl butyrate, vinyl isobutyrate,

vinyl valerate, vinyl caproate, vinyl enanthate, vinyl benzoate,

vinyl toluate, vinyl p-chlorobenzoate, vinyl ochlorobenzoate, vinylm-chlorobenzoate and similar vinyl halobenzoates, vinylp-methoxybenzoate, vinyl o-methoxybenzoate,vinyl p-ethoxybenzoate,methyl methacrylate, ethyl methacrylate, propyl methacrylate, butylmethacrylate, amyl methacrylate, hexyl methacrylate, heptylmethacrylate, octyl methacrylate, decyl methacrylate, methyl crotonate,ethyl crotonate and ethyl tiglate, methyl acrylate, ethyl acrylate,propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate,amyl acrylate, hexyl acrylate, Z-ethylhexyl acrylate, heptyl acrylate,octyl acrylate, 3,5,5-trimethylhexyl acrylate, decyl acrylate anddodecyl acrylate, isopropenyl acetate, isopropenyl propionate,isopropenyl butyrate, isopropenyl valerate, isopropenyl caproate,isopropenyl enanthate, siopropenyl benzoate, isopropenylp-chlorobenzoate, isopropenyl obromobenzoate, isopropenylm-chlorobenzoate, isopropenyl toluate, isopropenyl alpha-chloroacetateand isopropenyl alpha-bromopropionate;

Vinyl alpha-chloroacetate;vinyl alpha-bromoacetate, vinylalpha-chloropropionate, vinyl alpha-bromopropionate, vinylalpha-iodopropionate, vinyl alpha-chlorobutyrate, vinylalpha-chlorovalerate and vinyl alpha-bromovalerate;

Allyl chlorocarbonate, allyl forrnate, allyl acetate, allyl propionate,allyl butyrate, allyl valerate allyl caproate, diallyl phthalate,diallyl succinate,diethylene glycol bis(allyl-carbonate), allyl3,5,5-trimethylhexoate, allyl benzoate, allyl acrylate, allyl crotonate,allyl oleate, allyl chloroacetate, allyl trichloroacetate, allylchloropropionate, allyl chlorovalerate, allyl lactate, allyl pyruvate,allyl aminoacetate, .allyl acetoacete, allyl thioacetate,diallyl-3,4,5,6,7,7-hexachloro-4- endomethylene tetrahydrophthalate, aswell as methallyl esters corresponding to the above allyl esters, aswell as esters from such alkenyl alcohols as beta-ethyl allyl alcohol,betapropyl allyl alcohol, l-buten-4-ol, 2-methyl-buten-l-ol-4,2(2,2-dimethylpropyl)- l -buten-4-ol and l-pentene-4-ol;

Methyl alpha-chloroacrylate, methyl alpha-bromoacrylate, methylalpha-fluoroacrylate, methyl alpha-iodoacrylate, ethylalpha-chloroacrylate, propyl alpha-chloroacrylate, isopropylalpha-bromoacrylate, amyl alpha-chloroacrylate, octylalphachloroacrylate, 3,5,5-trimethylhexyl alpha-chloroacrylate, decylalpha-chloroacrylate, methyl alpha-cyano acrylate, ethyl alpha-cyanoacrylate, amyl alpha-cyano acrylate, amyl alphacyano acrylate and decylalpha-cyano acrylate;

Dimethyl maleate, diethyl maleate, diallyl maleate, dimethyl fumarate,dimethallyl fumarate, diethyl aconitate and glutaconate;

4. Organic nitriles such as acrylonitrile, methacrylonitrile,ethacrylonitrile, crotonitrile, and the like;

5. Acid monomers such as acrylic acid, methacrylic acid, crotonic acid,3-butenoic acid, angelic acid, tiglic acid, aconitic acid, and the like;

6. Amidcs such as acrylamide, alpha-methyl acrylamide, N- phcnylacrylamide, N-methyl, N-phenyl acrylamide, and the like.

The preferred monomers are liquid compounds soluble in the polyestercomponent. They will contain the group and preferably the latter will beattached to a negative radical such as a benzene ring, a chlorine atom,an ester linkage, a nitrile group or the like. They should be free ofcarboncarbon conjugated double bonds.

The monomer component or components may be employed over a relativelybroad range, but, usually, the amount thereof upon a weight basis willbe less than that of the polyester component. Usually, the percentage ofmonomer will fall within a range of about to 45 or 50 percent by weightof the total mixture of polyester and monomer. The preferred range ofmonomer is about to 40 percent, in most instances.

The catalysts of this invention can be used to cure the polyester resinsystems disclosed in co-pending application Ser. No. 782,735 (DisclosureNo. 2,917); application Ser. No. 782,710 (Disclosure No. 2,918);application Ser. No. 782,709 (Disclosure No. 2,919); application Ser.No. 782,748 (Disclosure No. 2,920); application Ser. No. 782,747(Disclosure No. 2,921); application Ser. No. 782,708 (Disclosure No.2,922); application Ser. No. 782,727 (Disclosure No. 2,923); applicationSer. No. 782,71 l (Disclosure No. 2,924); application Ser. No. 782,749(Disclosure No. 2,925); application Ser. No. 782,750 (Disclosure No.2,75 l application Ser. No. 782,759 (Disclosure No. 2,752); andapplication Ser. No. 782,757 (Disclosure No. 2,735 applicants in all ofthe aforegoing applications are E. E. Stahly and E. W. Lard; all of theaforegoing applications being filed on Dec. 10, 1968; each applicationhaving a common assignee with this application. Those applicationsdisclose polyester resin systems containing over 900 ppm. of inhibitor.

The curing time of the polyester resin systems varies between about 1minute and about 24 hours, but more generally, between about 30 minutesand about 4 hours. This time span depends, in part, upon the type ofpolyester resin, the amount of catalyst, the amount of inhibitor, and soforth. The curing temperature of the polyester resin systems variesbetween about 15 C. and about 250 C. Preferably, the

polyester resin system can be cured at room temperature 15 to 30 C.

As the scope of useful polyester resin systems is extensive, the type ofpromoter which can be used in those systems is also extensive. A fewexemplary promoters are given in the following paragraphs.

One of the promoter types which can be used in the polyester resinsystems is a cobalt salt which is capable of being dissolved in theresinous composition. Suitable soluble cobalt salts are such as cobaltnaphthenate, cobalt tallate, cobalt octoate or any other higher fattyacid salt of cobalt. The amount of cobalt salt can be varied from about0.001 to 0.3 percent of the salt calculated as dissolved metallic cobaltbased on the total weight of the resin components, catalyst and promotermixture employed. On the same basis, the preferred amount of cobaltmetal ranges from about 0.02 to 0.15 percent.

The vanadium promoters disclosed in US. Pat. No. 3,333,021 also areuseful.

Another useful promoter type material is a variety of amine promoters.Suitable amine promoters are disclosed in U.S. Pat. No. 2,480,928. Thepromoters are described therein as tertiary monoamines which containattached to the nitrogen atom two functionally aliphatic radicalsselected from the group consisting of alkyl hydrocarbons,hydroxy-substituted alkyl hydrocarbons and aralkyl hydrocarbons and onearomatic radical selected from the group consisting of arylhydrocarbons, azo-substituted aryl hydrocarbons, amino-substituted arylhydrocarbons, hydroxy-substituted aryl hydrocarbons, andaldehyde-substituted aryl hydrocarbons, and aldehyde-substituted aralkylhydrocarbons, and salts thereof. Specific examples of this class are thefollowing: dimethylaniline, diethylaniline, di-n-propylaniline,dimethylp-toluidine, dimethyl-o-toluidine, dimethyl-alphanaphthylamine,methyl benzyl aniline, pdimethylaminoazobenzene,N,N-dimethyl-m-aminophenol, phydroxy-N,N-di(beta-hodroxyethyl)aniline,pdimethylaminophenyl oxalate, p-dimethylaminophenyl acetate, andp-dimethylaminobenzaldehyde. Additionally, the promoter can be atertiary alkyl amine, a hydroxy alkyl amine or an acid salt thereof as apromoter. Exemplary of these types of promoters arediethylmethylolamine, triethylamine, triisopropylamine, trimethylamine,tri-isopropanolamine, ethyl diethanolamine hydrochloride and the like.Tertiary polyarnines are also effective for use in the instant manner,such as for example, tetramethylbutanediamine. The amount of aminepromoter useful in the practice of this invention va ries between about0.05 to 1.0 percent based on the resin components, catalyst andpromoter. These amine promoters can be used in conjunction with theabove cobalt promoters.

The polyester resin systems of this invention can also contain othercompatible additives, such as fillers (silica, etc.), 51:50,, boricacid, etc.

The following examples illustrate this invention. All percentages andparts therein are by weight, unless otherwise stated.

EXAMPLE 1 An uncured polyester resin system, containing 18.1 weightpercent fiber glass (silica), 1.5 weight percent cobalt octoate, 3.7weight percent Lupersol 224, 2.7 weight percent Lupersol 256, and 74.0weight percent polyester resin components, was prepared. The uncuredpolyester resin system also contained 1.0 mole percenttetrabromocatechol (inhibitor), based upon the above enumeratedmaterials. The polyester resin components were 10 moles diethyleneglycol, 4 moles maleic anhydride, moles chlorendric anhydride, 1 moleadipic acid and moles styrene. Before the styrene was added, thepolyester was prepared by heating the mixture of the diethylene glycol,the anhydridcs and acid in vacuo for 8 hours at temperatures up to 205C. At the end of this period, no further water was being evolved, andthe product was cooled. To the final mixture, the styrene was blended inwhen the product was cooled to 70 C. At the end of the styrene addition,the temperature was below 50 C. Lupersol 224 is a trade designation fora solution of 3,5-dirnethyl-3,5-dihydroxy-1,2- peroxycyclopentane (50percent), having an active oxygen content of 4.0 percent, which iscommercially available from the Lucidol Division of Wallace &. Tiernan,1nc. The organic ketone peroxide in Lupersol 224 is 3,5-dimethyl-3,5-dihydroxy-l ,2-peroxycyc1opentane, which has the formula:

(See US. Pat. No. 3,377,407.) Lupersol 256 is a trade designation for asolution of 2,5-dimethyl-2,5-bis(2-ethyl hexanoy1peroxy)hexane (90percent), having an active oxygen content of 6.7 percent, which iscommercially available from the Lucidol Division of Wallace 8: Tiernan,lnc. The uncured polyester resin system was prepared by weighing thepolyester resin into a beaker. The'following added in the order listed:(1) sodium methoxide, (2) cobalt octoate, (3) Lupersol 256, (4) Lupersol224. Each addition was followed by thorough mixing. The sample was thenpoured into a mold alternating layers of resin and fiber glass mattingand allowed to cure.

The mixed polyester resin system containing the catalysts and promoterswas cured by heating between 77" F. and 180 F. for 25 minutes. Thecuring is an exothermic autoaccelerating reaction. The resin systemgelled after 20 minutes and the peak temperature was 250 F. A we11-curedpolyester resin was obtained. After 24 hours, the flexural modulus was500,000 p.s.i. This example represents the preferred embodiment of thisinvention.

EXAMPLE 2 Example 1 was repeated, except that the inhibitor was picricacid (0.3 mole percent). A welhcured polyester resin was obtained.

EXAMPLE 3 Example 1 was repeated, except that the resin system contained12.5 weight percent glass, 1.5 weight percent cobalt octoate, 4.5 weightpercent Lupersol 224, 2.7 weight percent Lupersol 256, 0.2 weightpercent sodium methoxide, and 88.6 weight percent of the resincomponents (used in Example 1). The uncured polyester resin system alsocontained 0.2 mole percent picric acid. A well-cured resin was obtained.The cured resin had a modulus K of 136 p.s.i. after 2 hours, 159 p.s.i.after 4 hours, and 172 p.s.i. after 24 hours.

EXAMPLE 4 Example 3 was repeated, except that the inhibitor wastetrabromocatechol (1.0 mole percent). A well-cured polyester resin wasobtained.

EXAMPLE 5 Example 1 was repeated, except that the resin system contained20.4 weight percent glass, 1.5 weight percent cobalt octoate, 2.8 weightpercent Lupersol 224, 1.9 weight percent Lupersol 256, and 73.4 weightpercent of the resin components. The uncured polyester resin system alsocontained 1.0 mole percent tetrabromocatechol. The polyester componentswere 10 moles diethylene glycol, 5 moles maleic anhydride, 5 moleschlorendic anhydride, 10 moles styrene, and

0.02 mole cobalt naphthenate. A well-cured polyester resin was obtained.

EXAMP1=E6 Example 1 was repeated, except that the resin system containedl4.8 weight percent glm, 1.35 weight percent cobalt oetoate, 6.65 weightpercent Lupersol 244, 1.98 weight percent Lupersol 256, 0.18 weightpercent sodium methoxide, and 75.04 weight percent of the resincomponents (used in Example 5). The uncured polyester resin system alsocontained 0.25 mole percent tetrabromocatechol and 0.25 mole percentpicric. A well-cured resin was obtained. The cured resin had a modulus Kof 444 p.s.i. afler 24 hours.

EXAMPLE 7 Example 1 was repeated, except that the resin system contained19.0 weight percent glass, 1.35 weight percent cobalt octoate, 6.65weight percent Lupersol 224, 1.98 weight percent Lupersol 256, 1.20weight percent sodium methoxide, and 69.49 weight percent of the resincomponents (used in Example 5). 'lhe uncured polyester resin system alsocontained 0.25 mole percent tetrabromocatechol and 0.25 mole percentpicric. A well-cured resin was obtained. The cured resin had a modulus Kof 554 p.s.i. after 24 hours.

EXAMPLE 8 EXAMPLE 9 Example 1 was repeated, except that the inhibitorwas phenol (0.5 mole percent). A well-cured polyester resin wasobtained.

EXAMPLE 10 Example 1 was repeated, except that the inhibitor wasparacresol (0.3 mole percent). A well-cured polyester resin wasobtained.

EXAMPLE 11 Example 1 was repeated, except that the inhibitor washydroquinone (0.6 mole percent). A wellcured polyester resinwasobtained.7

EXAMPLE 12 Example 1 was repeated, except that the inhibitor wastertiary-butyl catechol (0.2 mole percent). A well-cured polyester resinwas obtained.

EXAMPLE 13 Example 1 was repeated, except that the inhibitor wastoluquinone (1.0 mole percent). A well-cured polyester resin wasobtained.

EXAMPLE 14 Example 1 was repeated, except that the inhibitor was 2,5-di-t-butylquinone (0.2 mole percent). A we1l-cured polyester resin wasobtained.

-1 EXAMPLE 15 Example 1 was repeated, except that the inhibitor wasp-octylphenyl salicylate (0.4 mole percent). A well-cured polyesterresin was obtained.

EXAMPLE 16 Example 1 was repeated, except that the inhibitor wasresorcinol monobenzoate (0.8 mole percent). A well-cured polyester resinwas obtained.

EXAMPLE 17 EXAMPLE 18 Example 1 was repeated, except that the polyesterresin was prepared and comprised as follows: A mixture of 70 parts byweight of an unsaturated polyester obtained from 2.7 moles of maleicacid anhydride, 4.4 moles of phthalic acid anhydride, 3.9 moles ofethylene glycol, and 3.4 moles of diethylene glycol (2,2'-dihydroxyethyl ether) with 30 parts by weight of styrene.

A well-cured polyester resin wm obtained.

EXAMPLE 19 Example 1 was repeated, except that the polyester resin wasprepared and comprised as follows: A mixture of 840 parts of diethyleneglycol, 159 parts of ethylene glycol, 592 parts of phthalic anhydrideand 588 parts of maleic anhydride was added to a reaction flask equippedwith mechanical stirrer, thermometer and a Dean-Stark water trap. Thereaction mixture was kept under an atmosphere of carbon dioxide duringthe entire course of the reaction. Following the addition of the mixtureto the flask, the mixture was heated to mobility at which time stirringwas commenced. At a temperature of 105 C., the mixture becamehomogeneous and started to esterify as manifested by the distillation ofwater. A controlled rate of heating (cooling needed at 100 C.) wasapplied so that after 1 hour, 150 C. was reached and after 4 hours, 190C. was reached. The temperature was then raised to 200 to 210 C. under avacuum of 2 mm. while still bubling in C0,. After heating for 3.5 hoursat 200 to 210 C., the polyester had an acid number of less than 40 andwas cooled to 100 C. and 1,040 grams of styrene containing 0.01 percentby weight hydroquinone was stirred in. The homogeneous clear mixture wasremoved from the flask and cured.

A well-cured polyester resin was obtained.

EXAMPLE 20 Example 1 was repeated, except that the polyester resin wasprepared and comprised as follows: A polyester resin cornposition wasmade by mixing 10.88 parts of phthalic anhydride and 7.21 parts ofmaleic anhydride with 11.20 parts of propylene glycol and 0.57 part ofethylene glycol. The mixture was esterified at 200 to 210 C. to an acidnumber of 50, cooled, and 14 parts of styrene was stirred in.

A well-cured polyester resin was obtained.

EXAMPLE 21 Example 1 was repeated, except that the polyester resin wasprepared and comprised as follows: A polyester resin was prepared byesterifying 13.4 parts of diethylene glycol, 2.94 parts of maleicanhydride and 13.15 parts of adipic acid at 205' to 210 C. in thepresence of 0.00416 pan of hydroquinone until an acid number of 30 wasreached.

The cooled polyester was converted to a liquid resin by the addition of24.8 parts of styrene which contained 0.00136 part of hydroquinone andcopper naphthenate sufiicient to yield a concentration of one part permillion of copper based on the finished resin.

A well-cured polyester resin was obtained.

EXAMPLE 22 Example 1 was repeated, except that the polyester resin wasprepared and comprised as follows: A dipropylene glycolmaleic anhydridepolyester resin was made by adding 17.45 parts of dipropylene glycol to12.50 pans of maleic anhydride. The mixture was esterified at 205 to 210C. to obtain a resin with an acid number of 25, and 15 pans of styrenewas added.

A well-cured polyester resin was obtained.

EXAMPLE 23 styrene.

A well-cured polyester resin was obtained.

EXAMPLE 24 Example 1 was repeated, except that Lupersol DDA-30 was usedinstead of Lupersol 224. Lupersol DDA-30 is the trade designation for astable, clear solution of methyl ethyl ketone peroxide in dimethylphthalate and diallyl phthalate. lt contains 30 percent methyl ethylketone peroxides, has an active oxygen content of 5.5 percent (min.),has an sp.gr. (25/25 C.) of 1.1128, and has a flash point (micro opencup) of2l5 to 220 F. (It is soluble in diallyl phthalate, dimethylphthalate, methyl benzyl phthalate, ethyl acetate, esters, ethers, andethyl alcohol; insoluble in water, carbon tetrachloride, cyclohexanone,and ethylene glycol; and moderately soluble in styrene, benzene, andtoluene.) Lupersol DDA-30 is commercially available from the LucidolDivision of the Wallace 8L Tieman, Inc.

A well-cured polyester resin was obtained.

EXAMPLE 25 Example 1 was repeated, except that Lupersol DDM was usedinstead of Lupersol 224. Lupersol DDM is the trade designation for aclear, colorless solution of methyl ethyl ketone peroxides andhydroperoxides in dimethyl phthalate. It is a water-white liquidcontaining 60 percent methyl ethyl ketone peroxides (as C,H, O,) andhaving an active oxygen content of 11 percent (min.). (It is readilysoluble in most synthetic resin monomers.) Lupersol DDM is commerciallyavailable from the Lucidol Division of the Wallace & Tieman, Inc.

A well-cured polyester resin was obtained.

EXAMPLE 26 Example 1 was repeated, except that Lupersol Delta was usedinstead of Lupersol 224. Lupersol Delta is the trade designation for aclear, colorless solution of methyl ethyl ketone peroxides andhydroperoxides in dimethyl phthalate. It is a water-white liquid with amethyl ethyl ketone peroxide content of 60 percent (as C,H,,O.) and hasan active oxygen content of 11 percent (min.), sp.gr. (25 C.) of 1.093(min.), and has a flash point (micro open cup) that is above 122 F. Itis soluble in alcohols, ethers, ketones, and acetate esters; insolublein water, glycerine, petroleum ether, cyclohexane, and mineral oil; andslightly soluble in chlorinated hydrocarbons, tricresyl phosphate,toluene, and dioctyl phthalate. Lupersol Delta is commercially availablefrom the Lucidol Division of the Wallace & Tieman, Inc.

EXAMPLE 2'! Example 1 was repeated, except that Lupersol Delta-X wasused instead of Lupersol 224. Lupersol Delta-X is the trade designationfor a clear, colorless solution of methyl ketone peroxides andhydroperoxides in dimethyl phthalate. Lupersol Delta-X is commerciallyavailable from the Lucidol Division of the Wallace 84 Tieman, Inc.

A well-cured polyester resin was obtained.

EXAMPLE 28 Example 1 was repeated, except that Lupersol DNF was usedinstead of Lupersol 224. Lupersol DNF is the trade designation for aliquid ketone peroxide solution that is both self-extinguishing andnon-shock sensitive. It is a water-white liquid containing 58 percentketone peroxides, has an active oxygen content of 10.6 percent and has asp.gr. (25 C.) of 1.0309. It is soluble in methyl ethyl ketone, ethylalcohol, methanol, ethylene glycol, ethyl acetate, ethyl ether, andnbutanol; and insoluble in tolulene, cyclohexane dibutylphthalate,tricresyl phosphate, carbon tetrachloride, and chlorobenzene. LupersolDNF is commercially available from the Lucidol Division of the Wallace &Tiernan, Inc.

A well-cured polyester resin was obtained.

EXAMPLE 29 Example 1 was repeated, except that the resin systemcontained 0.8 gram of cobalt accelerator 254, 3.0 grams of Lupersol 224,50 grams of resin components (used in Example 1), 0.7 gram of a 50/50mixture of sodium methoxide, and 0.2 gram mole percent picric acid. Thegel time wm 1.2 minutes and the peak temperature was 205 F. Theresultant polymer was rubbery and flexible after 24 hours, and 48 hoursof cure were required to reach 300,000 p.s.i. flexural strength.

EXAMPLE 30 Polyester composition A was prepared by admixing and heating(as in Example 1) 10 moles of diethylene glycol, 4 moles of maleicanhydride, 5 moles of chlorendic anhydride, 1 mole of adipic acid, molesof styrene, and about 0.02 mole of cobalt octoate. There was a totalhalogen content of about 25 percent.

EXAMPLE 31 Polyester composition B was prepared by admixing and heating(as in Example 1) 10 moles of diethylene glycol, 5 moles of maleicanhydride, 5 moles of chlorendic anhydride, and 10 moles of styrene.There was a total halogen content of about 25 percent. (A cobaltcompound, or other catalyst, must be placed in the composition before itcan be cured after storage.)

EXAMPLE 32 Polyester composition C was prepared by admixing and heating(as in Example 1) 10 moles of diethylene glycol, 5 moles of maleicanhydride, 5 moles of chlorendic anhydride, 10 moles styrene, and 0.02mole of cobalt octoate. There was a total halogen content of about 25percent.

EXAMPLE 3 3 Polyester composition D was prepared by admixing and heating(as in Example 1) 10 moles of diethylene glycol, 6.2 moles of maleicanhydride, 1.2 moles of tetrabromophthalic anhydride, 2.6 moles ofphthalic anhydride and 10 moles of styrene. There was a total halogencontent of about 9 to ll percent. (A cobalt compound, or other catalyst,must be placed in the composition before it can be cured afier storage.)

EXAMPLE 34 Polyester composition E was prepared by admixing and heating(as in Example 1) 10 moles of diethylene glycol, 6.2

EXAMPLE 35 Example 1 was repeated, except that initially 1.0 molepercent of tetrabromocatechol was admixed with polyester A and theadmixture was stored for l5 days at a temperature of 125 F. Theadmixture was cured using the same amount of catalysts as shown inExample l, gelling in 12 minutes, and the peak temperature was 205 F.The resultant polymer was wellcured.

EXAMPLE 36 Example 35 was repeated, except that the cobalt octoate wasnot placed in the admixture until just before the catalysts were added.A well-cured polymer was obtained.

EXAMPLE 37 Example I was repeated, except that initially picric acid 1.0mole percent) was admixed with polyester composition B and the admixturewas stored for 20 days at a temperature of 125 F. The admixture wascured, gelling in 15 minutes, and the peak temperature was 250 F. Theresultant polymer was well-cured.

EXAMPLE 3 8 Example 37 was repeated, except that polyester composition Cwas used and that the cobalt octoate wasnot placed in the admixtureuntil just before it was cured. A well-cured polymer was obtained.

EXAMPLE 39 Example 1 was repeated, except that initially2-nitro-resorcinol (1.0 mole percent) was admixed with polyestercomposition D and the admixture was stored for 40 days at a temperatureof 70 F. The admixture was cured using the catalysts of Example 1,gelling occurred in 5 minutes, and the peak temperature was 265 F. Theresultant polymer was well-cured.

EXAMPLE 40 Example 39 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition E) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 4] Example 1 was repeated, except that initiallytetrabromocatechol (1.0 mole percent) was admixed with polyestercomposition D and the admixture was stored for 15 days at a temperatureof F. The admixture was cured, gelling occurred in 10 minutes, and thepeak temperature was 210 F. The resultant polymer was well-cured.

EXAMPLE 42 Example 41 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition E) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 43 Example I was repeated, except that initially chloranil (1.0mole percent) was admixed with polyester composition D and the admixturewas stored for 15 days at a temperature of F. The admixture was cured,gelling in 5 minutes, and the peak temperature was 250 F. The resultantpolymer was well cured.

EXAMPLE 44 Example 43 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition E) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 45 Example 1 was repeated, except that initially 2-( 2-aminomethylamino)--nitropyridine (1.0 mole percent) was admixed withpolyester composition B and the admixture was stored for 60 days at atemperature of 70 F. The admixture was cured, gelling in 5 minutes, andthe peak temperature was 260 F. The resultant polymer was well-cured.

EXAMPLE 46 Example 45 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition C) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 47 Example I was repeated, except that initiallyp-quinonedioxime (1.0 mole percent) was admixed with polyestercomposition B and the admixture was stored for 80 days at a temperatureof 70 F. The admixture was cured, gelling in 5 minutes, and the peaktemperature was 250 F. The resultant polymer was well-cured.

EXAMPLE 48 Example 47 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition C) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 49 EXAMPLE 50 Example 49 was repeated, except that the cobaltoctoate was not placed in the admixture (containing polyestercomposition C) until just before it was cured. A well-cured polymer wasobtained.

EXAMPLE 5 l Example 1 was repeated, except that initially 1,4-naphthalenediol (1.0 mole percent) was admixed with polyestercomposition B and the admixture was stored for 30 days at a temperatureof 70 F. The admixture was cured, gelling in 8 to minutes, and the peaktemperature was 260 F. The resultant polymer was well-cured.

EXAMPLE 52 Example 51 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing the polyester composition C)until just before it was cured. A well-cured polymer was obtained.

EXAMPLE 53 Example I was repeated, except that initially2,5-dimethylp-benzoquinone (1.0 mole percent) was admixed with polyestercomposition 8 and the admixture was stored for 110 days at a temperatureof 70 F. The admixture was cured, gelling in 2 minutes, and the peaktemperature was 260 F. The resultant polymer was well-cured.

EXAMPLE 54 Example 53 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition C) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 55 Example I was repeated, except that initiallyZ-hydroxypyridine 1.0 mole percent) was admixed with polyestercomposition D and the admixture was stored for 30 days at a temperatureof 70 F. The admixture was cured, gelling in 8 to 10 minutes, and thepeak temperature was 260 F. The resultant polymer was well-cured.

EXAMPLE 56 Example 55 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition E) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 57 Example 1 was repeated, except that initially cyanogenbromide (0.5 mole percent in isopropanol 0.9 mole percent) was admixedwith polyester composition B and the admixture was stored for days at atemperature of 70 F. The admixture was cured, gelling in less than 2minutes, and the peak temperature was 260 F. The resultant polymer waswell-cured.

EXAMPLE 58 Example 57 was repeated, except that the cobalt octoate wasnot placed in the admixture (containing polyester composition C) untiljust before it was cured. A well-cured polymer was obtained.

EXAMPLE 5 9 Example 1 was repeated, except that Lupersol 6 was usedinstead of Lupersol 224. Lupersol 6 is the trade designation for bis(l-hydrocyclohexyl)peroxide. Lupersol 6, one part by weight, wasdissolved in methanol, 2 parts by weight, before it was used. Awell-cured polyester resin was obtained.

EXAMPLE 60 Example l was repeated, except that Lupersol 256 was replacedwith 2,5-dimethylhexane-2,5-dihydroperoxide. A well-cured polyesterresin was obtained.

EXAMPLE 61 Example 1 was repeated, except that Lupersol 256 was replacedwith Lupersol ll8. Lupersol l 18 has a minimum active oxygen content of7.66 percent and is 2,5-dimethylhexane-2,5-diperoxybenzoate, which hasthe following structural formula:

CH; CH:

A well-cured polyester resin was obtained.

EXAMPLE 62 Example 1 was repeated, except that Lupersol 256 was replacedwith Lupersol KDB. Lupersol KDB is a clear solution of di-t-butyldiperoxyphthalate (50.0 percent minimum content) in dibutyl phthalate.it has a minimum active oxygen content of 5.16 percent. di-t-butyldiperoxyphthalate has the following structural formula:

A well-cured polyester resin was obtained.

EXAMPLE 63 Example I was repeated, except that the Lupersol 224 wreplaced with:

A well-cured polyester resin wu obtained.

EXAMPLE 64 Example 1 was repeated, except that Lupersol 224 was replacedwith:

CH; OOH

CH: 1100 CHI A well-cured polyester resin was obtained.

EXAMPLE 65 EXAMPLE 66 Example 60 was repeated, except that the solventin the 1,2-

peroxycyclopentane solution was hexylene glycol. A wellcured polyesterresin was obtained.

EXAMPLE 67 Example 60 was repeated, except that the solvent in the L2-peroxyeyclopentane solution was a 50/50 mixture of water and hexyleneglycol. A well-cured polyester resin was obtained.

EXAMPLE 68 Example 6 was repeated, except that propylene glycol was usedin place of diethylene glycol. A wellcured polyester resin was obtained.

EXAMPLE 69 Example 65 was repeated, except that the1,2-peroxycyclopentane solution was comprised of 30 percent 335-dimethyl-3,5-dihydroxy-l,2-peroxycyclopentane, 12 percent water, 29percent trietryl phosphate and 29 percent N-alkyl-2- py'rrolidinone. Awell-cured resin was obtained.

It is claimed:

1. A catalyst for preparing a cured polyester resin, said catalystconsisting essentially of a mixture of 3,5-dimethyl-3,5-dihydroxy-1,2-peroxycyclopentane and 2,5-dimethyl-2,5- bis( 2-ethylhexano l peroxy)hexane, the weight ratio of said3,5-dimethyl-3,5-d11ydroxy-l,2-peroxycyclopentane to said2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxy)hexane ranging betweenabout 2:1 and about 4:1.

2. The catalyst of claim 1 wherein said catalyst contains at least 2percent by weight of sodium methoxide.

I i i l i

2. The catalyst of claim 1 wherein said catalyst contains at least 2percent by weight of sodium methoxide.